The appearance inspection process depends partly on manual work in which there are issues concerning detection accuracy and inspection efficiency. Tactile inspection, which is part of the appearance inspection, involves touching a target object with the palm of the hand to detect poor appearance, such as the distortion of product shape and unevenness of product surface. Such tactile inspection, involves repetitive motion and maintaining an awkward work posture for long periods of time, which may cause upper-limb disorders. Therefore, guidelines to reduce upper-limb load are required. However, few studies have evaluated that upper-limb load is related to tactile inspection quantitatively. This study targeted tactile inspection performed by workers. We focused on the factors affecting inspection accuracy to clarify the relationship between upper-limb load and inspection accuracy during tactile inspection. Ten healthy subjects participated in the experiment. Participants were asked to inspect an object with convex points at different heights. Evaluation involved two factors : one was the type-II error rate, which is the index of failure oversight, and the other was control force applied vertically to the object. The results showed that control force decreased when the wrist joint load increased, and inspection accuracy decreased with it. Furthermore, using the results of a previous study, an inspection condition considering both inspection accuracy and upper-limb load was derived. As a result, it was revealed that it is possible to reduce upper-limb load and improve inspection accuracy when the worker conducts inspections at chest height in front of the shoulder.

A roll box pallet (RBP) is manual cargo-handling equipment having four wheels. In occupational environments, some workers have injured their hands while performing transfer tasks using RBPs. The goal of this research was to develop an external attachment that concurrently protects workers' hands and ensures safe RBP operability. In this study, the three-dimensional accelerations of RBP movements during rotational transfer tasks were measured and the operability of RBPs was evaluated by the subjective assessment. Six males with three to twenty years of experience in operating RBPs (experienced males) and six males with no experience (inexperienced males) were required to perform the rotational movements of RBPs using two vertical handles. The interhandle distance was adjusted to 40, 50, 60, and 80 cm; for each distance, the loaded weights were varied at 0 and 50 kg. The results exhibited a significant difference in the acceleration patterns between the experienced and inexperienced males. The experienced males exerted higher anterior-posterior acceleration during the initial movement of RBPs, resulting in an operation that was less affected by superimposed weights. Moreover, the experienced males exerted higher lateral acceleration and assessed the operability as preferable at an interhandle distance of 80 cm.

Recently, the use of products with high-performance touch panels, such as smartphones, has spread rapidly. As a result, many people routinely use products containing touch panels and users' quality expectations for touch panels are increasing. In contrast, some products like printers still use low-performance touch panels because of cost restrictions. Since users' quality expectations for touch panels are increasing, it will be necessary for companies that manufacture products using low-performance touch panels to improve usability. In order to improve the usability products equipped with touch panels, companies must accurately understand the users' increasing quality expectations.

This study analyzed users' increasing quality expectations for touch panels by performing a Kansei evaluation for several smartphones. Moreover, this study proposes a method for developing product design guidelines to improve touch panel usability based on the aforementioned expectations. Furthermore, guidelines for improving the usability of printer touch panels were clarified by applying the proposed method. Subsequently, we applied the aforementioned guidelines to the touch panel of a printer and confirmed that the usability of the target printer's touch panel was indeed improved.

The proposed method enables an understanding of users' increasing expectations without being biased to the performance of current products. It is possible to improve the usability of touch panels effectively by applying the proposed method.

This paper applies virtual reality technology to propose a method of easily estimating sorting task aptitude. For the analysis of a sorting task, a task analysis apparatus to which actual equipment and virtual reality technology are applied was produced. The apparatus has the capability to determine that all of the defective products were detected in the sorting task, analyze the sorting task separately from the actual process, and set the task conditions, such as the conveyor speed and the types and locations of defective products, in a short period of time. The method comprises the steps of using cluster analysis based on the sorting task time on an actual conveyor to classify the subjects into groups according to their sorting task aptitude and using the cross-validation method to select an estimation model for estimating the sorting task aptitude on the actual conveyor from the sorting task time in a virtual task area. Finally, the present method was applied to estimate the sorting task aptitude of workers in the process of producing food products, and review the relationship between the sorting task aptitude and personal arrangement.

Experiments on useful field-of-view (UFOV) and eye-head coordination were employed to propose an evaluation method for using it during visual information processing, without distracting the subject's main task. Eye and head movement were measured under the condition in which the subject's UFOV was controlled. In particular, subjects performed two tasks: a simple task for inducing a decrease in alertness and a visual target detection (VTD) task for inducing eye-head coordination. In the simple task, the subjective arousal level and UFOV were measured. UFOV was measured by subjective response to a visual target. As a result of conducting the simple task, it was found that UFOV was narrowed at the time of low arousal. In the VTD task, eye and head movement were measured under the condition in which visual angular distance to the visual target was controlled in steps. As a result of conducting the VTD task, it was found that eye-head coordination to the visual target was influenced by UFOV, eye movement precedes viewing a visual target inside of the UFOV, and head movement precedes viewing a visual target outside of the UFOV. Furthermore, it was indicated that it is possible to detecting narrowed UFOV using the relation between visual angular distance to visual target and response time lag of eye and head movement.

Some assistive products have been developed to provide gait assistance for elderly people. They support the gait motion of elderly people by including a control system. In this study, an assisting effect for normal walking using a four-wheeled walker equipped robotics technology was investigated for walking velocity, an acceleration applied to the walker, and the muscular load on the users. The four-wheeled walker is an assistive product for elderly gait. Some sensors and motors were incorporated in the walker using robotics technology. Participants were elderly males and females aged from 70 to 81 years old. They walked with two types of walkers on five road conditions: gentle and steep downhills, flat road, and gentle and steep uphills. One walker was that with robotics technology and the other was a ready-made walker without robotics technology. The participants walked with the four-wheeled walkers using two handle conditions: handgrip and armrest types. In addition to a participant's own power, the robotics technology gave the participant external propulsion power; therefore, the walking velocity was faster than the ready-made walker. However, the walker with robotics technology reduced the muscular load on the participant compared to the ready-made walker. The walker with robotics technology could support a normal walking gait and simultaneously alleviate the muscular load on elderly users.

Lately, there has been more research interest regarding the processes of design activity. It can be stated that there are two types of design activity: design activity for commissioned tasks, in which the designer receives the customer's problems and needs, and design activity for spontaneous tasks, in which the customer's problems and needs are not given. Previous studies mainly focused on the work processes for commissioned tasks, disregarding spontaneous tasks. To clarify the features of processes for spontaneous tasks, we conducted an empirical investigation of the content designer's design activity. The data was collected utilizing a questionnaire that was repeatedly taken throughout the actual work period, and a retrospective report method. The constitution of five typical actions (problem analysis, solution design, solution implementation, solution evaluation, and others) in the processes for both tasks were measured and compared. Results suggest the processes for spontaneous tasks have the ordered actions, contain little problem analysis, and have a high percentage of solution design after the designer has completed the outline of the outcome. This indicates the processes for spontaneous tasks have the features of possibility of structuring, self-preference centrality, indeterminateness of designed outline, and inheritance. These findings can be beneficial to determining a practical policy and tools for designer support.